package org.seefly.iprint.utils;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.util.Random;

/**
 * 
 * 验证码工具类
 * @author liujianxin
 * @date 2018年3月24日 下午6:20:32
 * @version 1.0.0
 */
public class CheckCodeUtil {





    public static String getCode(BufferedImage bufferedImage) {
        //int charNum = 4;
        int width = 30 * 4;
        int height = 30;
        // 2.获得绘图对象
        Graphics graphics = bufferedImage.getGraphics();

        // 3、绘制背景颜色
        graphics.setColor(Color.YELLOW);
        graphics.fillRect(0, 0, width, height);

        // 4、绘制图片边框
        graphics.setColor(Color.BLUE);
        graphics.drawRect(0, 0, width - 1, height - 1);

        // 5、输出验证码内容
        graphics.setColor(Color.RED);
        //设置字体样式会在linux系统上有问题。
        graphics.setFont(new Font("宋体", Font.BOLD, 20));

        // 随机输出4个字符
        Graphics2D graphics2d = (Graphics2D) graphics;
        String s = "ABCDEFGHGKLMNPQRSTUVWXYZ23456789";
        Random random = new Random();
        // session中要用到
        String msg = "";
        int x = 5;
        for (int i = 0; i < 4; i++) {
            int index = random.nextInt(32);
            String content = String.valueOf(s.charAt(index));
            msg += content;
            double theta = random.nextInt(45) * Math.PI / 180;
            // 让字体扭曲
            graphics2d.rotate(theta, x, 18);
            graphics2d.drawString(content, x, 18);
            graphics2d.rotate(-theta, x, 18);
            x += 30;
        }
        // 6、绘制干扰线
        graphics.setColor(Color.GRAY);
        for (int i = 0; i < 5; i++) {
            int x1 = random.nextInt(width);
            int x2 = random.nextInt(width);

            int y1 = random.nextInt(height);
            int y2 = random.nextInt(height);
            graphics.drawLine(x1, y1, x2, y2);
        }

        // 释放资源
        graphics.dispose();
        return msg;
    }

}
